Dyestuffs of the diphenylamine series



Patented Oct. 24, 1939 UNITED STATES PATENT OFFlCE DYE STU'FFS OF THE DIPHENYLAMINE SERIES Hans Krzikalla and Heinz Pardon, Ludwigshafenon-the-Rhine, and Fritz Hess, Frankfort-onthe-Main, Germany, assignors to General Aniline Works, Inc., New .York, N. Y., a corporation of Delaware No Drawing. Application December 31, 1936, Se-

rial No. 118,584. 1936 8 Claims.

in which R1 and R2 are hydrogen, alkyl, cycloalkyl or aralkyl radicles, X1 and X2 are hydrogen or any substituents free from a negative action and Y1 and Y2 are hydrogen or any desired substituents. As' suitable dinitrobenzenes having exchangeable substituents may be mentioned for example dinitrohalogen benzenes and dinitroalkoxybenzenes.

The reaction is generally speaking carried out in aqueous or aqueous-alcoholic solutions, advantageously in the presence of agents capable of binding acids, as for example the hydroxides or carbonates of the alkali or alkaline earth metals. The dyestuffs obtainable in the said manner are especially suitable for dyeing leather; they dye it yellow to brown shades, the dyeings having a very good penetration. The dyestuffs may also be used for dyeing wool and silk, very uniform dyeings being obtained. They are also suitable for dyeing wood thoroughly.

The following examples will further illustrate how our invention may be carried out in practice but the invention is not restricted to these examples. The parts are by weight.

Example 1 260 parts of 1-dimethylamino-4-aminobenzene-3-thiosulphonic acid are heated with 325 parts of 2,4-dinitro-1-chlorbenzene-6-sulphonic acid sodium salt, 210 parts of sodium bicarbonate and 3000 parts. of water for several hours at from to C. The hot reaction solution is filtered if necessary, the filtrate is acidified and the yellow-green dyestufi thus separated is filtered off by suction. It dyes leather yellowbrown shades, the dyeing being thorough.

A similar dyestufi is obtained by using 2,4- dinitro-l-chlorbenzene G-carboxylic acid or 2,4- dinitro-1-methoxybenzene-6-carboxylic acid instead of 2,4-dinitro-l-chlorbenzene-S-sulphonic In Germany January 22,

(Cl. 260-400) The present invention relates to new dystuffs acid. under the same conditions. If l-dimethylaminoi-aminobenzene-t-thiosulphonic acid be caused to react with 2,6-dinitro-1-chlorbenzene 4-sulphonic acid under the above conditions, a dyestufi is formed which thoroughly dyes leather violet-brown shades.

Example 2 50 parts of the sulphate of l-dimethylaminolaminobenzene are dissolved in a mixture of 250 parts of water and parts of alcohol, the solution is rendered alkaline with caustic soda solution and then there are added thereto 20 parts of sodium bicarbonate and a solution of 67 parts of 2,4-dinitro-l-chlorbenzene-G-sulphonic acid sodium salt in 250 parts of water. After the whole has. been heated for about 2 hours at from 80 to 90 C., the resulting dyestuff is salted out with parts of potassium chloride, filtered oiT by suction and dried. The dyestufi thus obtained dyes leather thoroughly brown shades.

Similar dyestuiTs are obtained under the same conditions while using l-diethylaminoi-aminobenzene, l-dihydroxyethylamino 4 aminobenzene, 1 hydroxyethyl-benzyl-amino 4 aminobenzene, 1-hydroxyethyl-sulphobenzyl-amino-4- aminobenzene, 1-hydroxyethyl-cyclohexylaminoii-aminobenzene or 1-methylamino-2-methyl-4- aminobenzene instead of l-dimethylamino-iaminobenzene.

Example 3 26 parts of 1-dimethylamino-4-aminobenzene 3-sulphonic acid are heated for from 5 to 6 hours at about 100 C. with 28 parts of 2,4-dinitro-1- chlorbenzene-6-carboxylic acid, 70 parts of potassium carbonate and 300 parts of water. After cooling, the separated reaction product is filtered off by suction, dissolved in water and the solution filtered. By acidification with hydrochloric acid, the dyestuff formed is precipitated. It is filtered off by suction, washed and dried. The dyestuff thoroughly dyes leather brown shades.

A similar dyestufi is obtained if 2,4-dinitro-1- chlorbenzene-S-sulphonic acid be employed instead of-the corresponding carboxylic acid.

What we claim is:

1. As new products the diphenylamines of the general formula wherein Ar stands for the radicle of a dinitrobenzene mono sulphonic acid, wherein R1 and R2 stand for a member of the group consisting of hydrogen, lower alkyl, cyclohexyl and benzyl, wherein X1 and X2 stand for a member ofthe group consisting of hydrogen, alkyl and alkoxy groups, and wherein Y1 and Y2 stand for a member selected from the class consisting of hydro.-.

gen and the sulphonic and thiosulphonic acid groups, at least one of the members marked Y1 and Y2 being hydrogen.

2. As new products the diphenylamines of the general formula wherein Ar stands for the radicle of a dinitrobenzene mono sulphonic acid, wherein R and R2 stand for lower alkyl, and wherein Y1 and Y2 stand for a member selected from the class con sisting of hydrogen and the sulphonic and chicsulphonic acid groups, at least one of the members marked Y1 and Y2 beinghydrogen.

3. As new products the diphenylamines of the general formula wherein Ar stands for the radicle of a dinitro benzene mono sulphonic acid, and wherein Y1 and Y2 stand for a member selected fromthe class consisting of hydrogen and the sulphonic and thiosulphonic acid groups, at least one of the members marked Y1 and Y2 being hydrogen.

4. As new products the diphenylamines of the t 1 general formula CH SaOzH /N lTL-Ar OH: H

wherein Ar standsfor the radicle of a dinitroy I benzene sulphonic acid.

7 6. As a new product the diphenylamine of the formula SzOzH N02 "7 As a-new product the diphenylamine of the formula 7 I "S1013 om CH:

CH: H

. j OQN 8. As a new product the diphenylamine of the formula CH S9313 N0\2 N-'. If No: CH3 H HANS KRZIKALLA. HEINZ PARDON. FRITZ HESS. 

